The L-Birds

Liaison aircraft

September 1, 1991

Fun warbird flying on the cheap

Think of a warbird, and what comes to mind? A P-51 Mustang, its 12 exhaust stacks snarling with raw-boned military power, perhaps. Or you might envision a P-38, its twin engine nacelles flowing back to a pair of rakish tails. If you're a fan of modern air might, the image of a F-15 might spring to mind, afterburners in full plume and carrying enough armament to level Tacoma, Washington.

Chances are, though, that you didn't think of a warbird with, say, a tiny, 65-horsepower engine, high wing, and a top speed about that of an economy car. Armament? The.45-caliber pistol on the pilot's hip. Afterburners? Only if the back-seater throws a lighted cigar out the window and catches the tail feathers on fire. And though certainly not in the league of the P-51 or F-15, this airplane — actually a whole class of airplanes — easily qualifies as a warbird.

They are known — today, at least — as L-birds. As in liaison. (When they were in service, the liaison aircraft were more likely to be called Grasshoppers or, as the Brits said, Flitfires. The colloquialism L-bird seems to have stuck among those restoring them.) Begun just before the outbreak of World War 11, the U.S. Army's liaison aircraft program lasted, in various guises, through Vietnam, providing vital reconnaissance information, furnishing transportation, and helping to create a few war stories for their pilots. Although in the beginning of the war there was some opposition to using light airplanes, they soon proved their worth. For cheap, efficient transportation, the L-birds couldn't be beat. They could get into and out of fields, roads, valleys, ravines, you name it that were a difficult trek by jeep.

With the requirements and missions determined — the airplanes would be observation platforms primarily, used to spot enemy gun emplacements and troop movements — general aviation manufacturers set about bidding for the potentially lucrative liaison contracts. Some built from scratch specialized models, while others used off-the-shelf airplanes modified for the liaison role.

Stinson fell into the former category, producing the L-1 in 1940. Up to that time, the Army Air Corps had been using the North American O-47 as an observation platform. Unfortunately, the O-47 required a fair amount of prepared runway and was ill-suited to low and slow reconnaissance flying. The Army, convinced that a slow-landing, slow-flying airplane better suited the needs of the ground troops, awarded three prototype contracts, one each to Stinson, Bellanca, and Ryan.

Not surprisingly, given the Army's requests for low stall speeds and slight emphasis on top speed, all three airplanes were high-wing, conventional-gear, tandem-seaters with large wings and various high-lift devices. The Stinson, called the YO-49 at the time, carried a 295-hp Lycoming radial, while the Bellanca YO-50 employed a 420-hp Ranger in-line, and the Ryan YO-51 used a 440-hp Pratt & Whitney R-985. Maximum gross weights ranged from 3,300 pounds for the Stinson to 4,200 pounds for the Ryan.

Stinson won the contract, largely because the airplane was slightly lighter and cheaper, and thus was born the L-1. With a 42-foot wingspan, full-span leading-edge slats, drooped ailerons, and huge flaps, the Stinson was capable of stunningly slow flight. Its top speed was about 106 knots, with a landing speed of around 25 knots. It was in many ways better at its job than was the O-47 but still could not operate out of very short bush (and front-line) strips and required as much maintenance as its predecessor.

General aviation manufacturers in 1941, hearing that the observation aircraft was not living up to original promises, began pressuring the military for a different kind of liaison aircraft. Representatives traveled to Washington, D.C., for a presidential conference on military aviation and at first found their calls for use of light aircraft falling upon deaf ears. But they persevered and, with a successful demonstration of the light airplanes' performance to the Army in late 1941, began to make inroads.

William T. Piper laid out a number of uses the light airplanes — at the time, Cubs, Taylorcrafts, Aeroncas could perform in the military. These included "semi-military" roles such as control of troops in unfamiliar terrain, medical evacuation, communications, patrol, and observation. In the "nonmilitary" category, Piper listed stimulation of flying activity for military personnel and coordination of the Civilian Air Reserve.

With the military warming to the charms of light airplanes, the manufacturers set about modifying existing models. Taylorcraft changed side- by-side seating to tandem and created what would be called the L-2. Still powered by the 65-hp Continental of the civilian version, the L-2 nonetheless had much more window area and provisions for the heavy radio gear of the time. The pilot sat up front with the observer behind.

Hot on the heels of the L-2 were the Aeronca Champ-based L-3 and the J-3 Cub-based L-4. Like the Taylorcraft entry, the L-3 and L-4 were powered by the C-65 Continental and had top speeds of about 70 knots, with landing speeds below 30 knots. (The designations, by the way, were issued as the aircraft were accepted by the military.) For their roles, the Champ and Cub both were modified with greater glass area, a clear greenhouse, and space for radio gear. As in prewar America, the little tandem two-seaters had by 1944 become ubiquitous at the front lines, ferrying personnel and messages at a fraction of the cost of other aircraft. What's more, they were fast proving their worth by landing in impossibly small fields and roads.

With the L-2, L-3, and L-4 laying important groundwork for further liaison designs, more manufacturers entered the fray. Stinson came back with a modified Voyager, to be termed the L-5; a purpose-built model from Interstate Aircraft, powered by a geared 115-hp Franklin, came on as the L-6. In all, more than 10,000 airplanes were used by the Army Air Corps during World War II, the majority of them the "Cub-type" models. Postwar liaison airplanes continued to be produced, among them: the L-17 (a Navion in olive drab) and the O-2 (a Skymaster used during the Vietnam conflict). Another post-World War II design, Cessna's L-19 Bird Dog, marked an interesting reversal of the practice of converting a civilian design into a liaison model. Predating the Cessna 170B by three years, the L-19 employed mammoth Fowler flaps in place of the straight 170's plain flaps — as well as a tremendously large greenhouse and tandem seating. You could say the 170B trickled down from the L-19.


Liaison aircraft of all types, but primarily of the World War II vintage, are expected at the first "Gathering of L-birds" sponsored by the International Liaison Pilot and Aircraft Association. We are here in San Antonio a day before the event kicks off to get a total-immersion course in the L-birds.

Bill Hancock has offered me a ride in his pristine L-4; his longtime friend, Baylor Randle, sits in the front seat. Randle and Hancock are members of both ILPA and the Alamo Liaison Group. The ALG has at Cannon Field a complete collection of World War II liaison aircraft, including what is believed to be the only flying L-1 Stinson. The 40 members of ALG individually or in partnerships own more than 20 flying L-birds; there are more in restoration.

Although the military markings are authentic, I find myself still not believing the L-4 is a warbird. Randle taxis out to the grass surface at Cannon Field, turns around at the end of the grass strip, and advances the throttle. No one would confuse the L-4 for a Spitfire, but it trundles off nonetheless, and we make a low pass for the photographer. Okay, it might be a bona fide warbird, but it flies just like a J-3. It is slow and a bit sluggish in response to control inputs, but flying low over the Texas countryside, the little Piper is so clearly in its element, you end up believing all is right with the world. And there's something, too, about the trim military markings and sparse interior. It might be a J-3 at heart, but there's something more, something special about this L-bird.

You can imagine flying at the front lines, treetop level, searching for tank tracks, enemy positions. Imagine wondering about gunfire from the ground and fighters from above. Actually, during World War II, there were few casualties. The liaison aircraft were so much more maneuverable than armed fighters that evasion was a fairly simple matter. Legend holds that one German pilot, unable to shoot down a liaison aircraft, in desperation simply flew by and clipped the offender's wing.

Like Hancock, Randle owns an L-bird; his is an L-2 Taylorcraft. He's been flying it for two years after a one year restoration. ILPA President Bill Stratton had brought the L-2 in from Arizona for an ALG restoration. Randle became involved in the process and ultimately bought the airplane from the group. He says that all told, he has about $12,000 into the project. An already restored example might fetch from $15,000 to $20,000, and, according to Randle, finding parts for either the Cub, Taylorcraft, or Aeronca models is no problem at all. (The vast majority of the pieces on these airplanes are the same as for the civilian versions, and these are easily attainable.) So far, the premium for an L-bird compared to the same model of civilian background is minimal. Which means that, for about the price of a 1957 Skyhawk, you can, like Randle, have a museum-quality, flying warbird, one that turns heads on airport ramps and offers substantial emotional payback hour after hour.

Randle certainly is not alone in his love of the L-bird. At the ILPA gathering, more than 150 pilots, restorers, and well-wishers arrived. Despite high winds, 20 aircraft made the pilgrimage to Cannon Field, among them a stunning L-19 Bird Dog in Japanese colors and a pair of L-17 Navions, one so shiny you had to wear sunglasses around it. There were no dogs, and even those in mid-restoration reflected a level of care and seriousness unexpected at this investment level.

More than a mutual appreciation for warbirds in general and liaison aircraft in particular, the gathering at Cannon Field felt like family. Low- key would best describe it, with none of the "don't touch that" attitude found around costlier machinery. The L-birds are honest-to-olive-drab warbirds, yes, but they can be had by the average Joe. Today, with the help of, among others, ILPA, ALG, and the many pilots still flying them, the L-birds remain important symbols of bygone aviation. And, perhaps, the last affordable warbirds.